The effect of Ti and C on the phase evolution and magnetic properties of Pr_9Fe_(bal)Ti_xB_(11-y)C_y (x=G-4, y=0-11) nanocomposites

摘要

Phase evolution, microstructure, and magnetic properties of melt-spun Pr_9Fe_(bal)Ti_xB_(11-y)C_y (x=0, 2.5, and 4, y=0-ll) ribbons have been investigated. For Pr_9Fe_(bal)Ti_xB_(11-y)C_y series ribbons, addition of Ti suppresses the formation of metastable Pr_2Fe_(23)B_3 phase and ensures the existence of a large amount of magnetically hard Pr_2Fe_(14)B phase in the ribbons. However, the increase of C substitution in the Pr_9Fe_(bal)Ti_(2.5)B_(11-y)C_y (y=0-5.5) ribbons diminishes the B_r,_iH_c, and (BH)_(max) monotonically, which comes from the increase of volume fraction of Pr_2Fe_(17)C_z and alpha-Fe phases and the rapid decrease of the 2:14:1 phase. Only in the higher Ti content Pr_9Fe_(bal)Ti_4B_(11-y)C_y ribbons, a slight C addition cannot only form the Pr_2Fe_(14)(B,C) phase but also refine the grain size, giving rise to the improvement of magnetic properties. The optimal properties of B_r=94 kG, _iH_c=11.1 kOe, (BH)_(max)=18.0 MGOe, alpha=-0.207 percent/ deg C, and beta=-0.6l2 percent/ deg C are achieved in Pr_9Fe_(bal)Ti_4B_(10.5)C_(0.5) nanocomposites.